The experiments presented in this proposal are intended to distinguish between two hypotheses about the function of the hippocampus. Some researchers believe that the hippocampus is necessary to remember where and when events have taken place (spatial hypothesis). Other researchers believe that the hippocampus is necessary to associate stimuli with one another, and allows representational flexibility (relational/flexibility hypothesis). Both of these hypotheses can explain much of the animal literature that has examined the effects of hippocampal lesions. These hypotheses do, however, make different predictions in specific situations. The spatial hypothesis predicts that lesions of the hippocampus will only affect learning [unreadable] situations that have spatial or temporal location as critical elements of the learning episode. The [unreadable] relational/flexibility hypothesis predicts that lesions of the hippocampus will not only effect situations that have spatial or temporal location as critical elements, but will also effect non-spatial learning situations that require representational flexibility. Thus, experiments that evaluate representational flexibility while holding spatial and temporal cues constant (rendering these cues irrelevant) are critical for distinguishing between these views. The experiments proposed here use a procedure that has been shown to demonstrate a phenomenon known as value transfer. The value transfer procedure will allow for an evaluation of representational flexibility while holding spatial and temporal information constant. Thus, these experiments will allow for a critical evaluation of the theories of hippocampal function. [unreadable] [unreadable]